Our Planets

Solar System Montage

This montage of Voyager spacecraft pictures shows the eight planets, plus four of Jupiter's moons, sprawled against the backdrop of the Rosette Nebula and on the horizon of Earth's moon. In addition to the planets and moons seen in this simulated photo, our solar system contains a star, asteroids and comets, and dwarf planets such as Pluto.

Though one of our nearest neighbors, Mars is still 43 million miles (69 million kilometers) from Earth, illustrating the nearly incomprehensible vastness of our solar system. Scientists are working to unravel the mystery of Mars's climate—evidence of water on the red planet will hold clues about life on Mars, as well as the potential for life elsewhere in the universe.

Streams of charged particles blasted from the sun collide with Saturn's magnetic field, creating an aurora on the planet's south pole. Unlike Earth's relatively short-lived auroras, Saturn's can last for days. Scientists combined ultraviolet images of the auroras, taken by Hubble over a period of days, with visible-light images of the ringed planet. In this view the aurora appears blue because of the ultraviolet camera, but a Saturn-based observer would see red light flashes.

nce classified as a true planet, icy Pluto is now considered one of the more than 40 dwarf planets in our solar system. Seen here with its three known moons, Charon, Nix, and Hydra, Pluto is a member of a group of objects that orbit in a disklike zone beyond the orbit of Neptune called the Kuiper belt.

Named after the king of the Roman gods, Jupiter is the giant of our solar system. Its stripes are dark belts and light zones created by strong east-west winds in the planet's upper atmosphere. Within these areas are huge storm systems that have raged for years. The Great Red Spot, one such giant spinning storm, has existed for at least three centuries.

The sun's outermost region, called the corona, shines like a halo around the moon during a total solar eclipse. Such eclipses occur when a new moon passes in front of the sun. They don't happen often—only about once a year—since the tilted orbits of the sun, moon, and Earth make their alignment rare. Total solar eclipses are of special interest to astronomers because it is the only time the sun's corona can be seen from the Earth's surface.

This montage of photos, taken by various NASA spacecraft, shows the order of planets in the solar system. Mercury, the closest planet to the sun, is at the top, followed by Venus, Earth (with its moon), Mars, Jupiter, Saturn, Uranus, and Neptune.